1. Field
The following description relates to a method and apparatus for controlling power in a wireless power transmission system.
2. Description of Related Art
Wireless power refers to energy transferred from a wireless power transmitter to a wireless power receiver, for example, through magnetic coupling. A wireless power transmission system includes a source device and a target device. The source device may wirelessly transmit power, and the target device may wirelessly receive power. The source device may be referred to as a wireless power transmitter, and the target device may be referred to as a wireless power receiver.
The source device includes a source resonator, and the target device includes a target resonator. Magnetic coupling or resonance coupling may be formed between the source resonator and the target resonator.
Due to characteristics of a wireless environment, a distance between the source device and the target device, or matching requirements matching the source resonator and the target resonator, may be changed, which may result in a change in power transmission efficiency. However, a constant power transmission efficiency may be needed. To maintain the constant power transmission efficiency, a resonance frequency may need to be tracked accurately.